by Tim James
Most people avoid mercury for this very reason but, during the nineteenth century, warm mercury nitrate was used as a key ingredient in preparing hat felt. Sure enough, people in the hat industry soon got a reputation for being a few electrons short of an atom, hence the term “mad as a hatter.”16
THE FIRE WITHIN
Running all these reactions is exhausting for your body, requiring a constant supply of energy to stay alive, so you obtain it by taking in sugar and setting fire to it.
In a chemical context, sugar doesn’t refer to one chemical but a collection of them. They’re all made from carbon, oxygen, and hydrogen atoms looped into hexagons or pentagons, and the stuff in your kitchen is a mixture of two kinds called sucrose and fructose. The different types of sugar you can buy, such as granulated, powdered, icing, etc., refer to the size of crystals rather than the chemicals themselves.
Most of the food we eat contains sugars, which the body breaks into the smallest type, glucose (C6H12O6). The glucose molecules then enter a sequence of reactions that convert them into water and carbon dioxide. The water is lost through sweat and the carbon dioxide dissolves into your blood where it is carried to the lungs and breathed out. The air you’re exhaling now is made from the food you ate this morning.
The original C, H, and O atoms are then repackaged into a highly unstable molecule called adenosine triphosphate, or ATP for short. ATP has a chain of phosphorus oxides hanging off it, which will detach at any given moment, releasing light and heat as they do. This energy can be absorbed by other molecules and gets used to drive all the reactions in a cell.
The whole procedure is controlled by molecular machinery swinging in and out to ensure the correct reactions happen at the correct time, and its discoverer, Hans Krebs, scooped the Nobel Prize for mapping the whole carnival.
This is the reason we need food in the first place. Without sugars we couldn’t supply energy to drive all the other chemical reactions that make us a living thing. With the exception of one species (Spinoloricus cinziae, which seems to have evolved a different way of getting energy), every creature on Earth carries out Krebs’s reaction.
It’s called respiration from the Latin spirare (to breathe) and it’s the same thing, chemically speaking, as fire. Some chemical reacts with oxygen, producing carbon dioxide, water, heat, and light in the process. We are all walking fire factories.
The only reason we’re not in danger is because it happens in several stages and on a very small scale. Just as well, because otherwise we’d burst into flames spontaneously. Speaking of which …
THE FURNACE WITHIN
The earliest record of spontaneous human combustion was the death of an unnamed Polish knight during the early sixteenth century under the reign of Queen Bona Sforza. The account appears in a 1654 book written by Thomas Bartholin who heard it as a secondhand account from Adolphus Vorstius, who heard it from his father, who claimed he once saw a document where it was written.17 Originally in Latin, the brief description translates as “he drank two cups of warm wine, then belched flames and was toasted.”
Spontaneous human combustion (SHC) is a controversial subject because nobody agrees on whether it happens. The idea that a person can catch fire without external ignition is very dramatic but apparently so rare that solid research is impossible to find. It’s not like you can study a group of people and see which one of them spontaneously combusts. It’s spontaneous.
Most SHC reports are like those of the Polish knight above; spurious secondhand descriptions and probably nothing more than ghost stories. Plus, the accounts that do give details are usually easy to explain. But it’s an interesting topic that captures the imagination so it’s worth looking into.
In most cases of SHC, the remains of a human body are found charred or melted with the exception of the feet and hands. The bones are turned to ash and, in most instances, the surrounding furniture is untouched.
Let’s address the bones turning to ash first. Many people argue that the temperature of such fires must be fierce in order to have such an effect. After all, the furnaces in crematoriums typically run to over 980°C.
However, the need for these high temperatures is because crematoriums have to burn a body quickly. A flame of a few hundred degrees is still enough to turn bones to ash provided it’s left for several hours. If you have a fuel source that lasts that long, there’s no mystery.
Explaining the fuel is the next task and in 1998 a scientist named John de Haan conducted a series of experiments in which he wrapped a pig carcass in cloth and set fire to one corner. Once the ignition had been provided, the water content of the pig boiled away and the dry carcass continued burning for five hours, destroying everything apart from the trotters.18 The explanation for this gruesome demonstration is “the wick effect.”
The subcutaneous fat of most mammals is flammable so, if the skin is broken, it can melt and leak into the surrounding cloth. The fabric is now doused in liquid fat and will burn like a candle wick for hours, using the full supply of body fat as fuel. This also explains why feet and hands are the only things left over; they have very little fat content so the fire leaves them unscathed.
So how come the rest of the room is always left alone? We’re used to hearing about fires getting out of control and buildings burning to the ground because fire will supposedly spread and destroy everything in its path. But if we really think about it, we know that isn’t true.
Most fires stay put and combust upward, not outward. Unless the ceiling is very low a fire will usually have nothing else to burn once the fuel is exhausted. Think of how you’re able to stand right beside a bonfire or hold a flaming match without your skin catching fire. Or think of all the exercise books sitting in chemistry labs the world over, inches away from Bunsen burners, none of them burning.
You can hold a piece of tissue paper an inch from a flame and it still won’t catch. Even if you waft it through the fire itself, it will only warm up.
Fires that do spread and make the news are usually the result of direct contact. A forest fire proliferates because the trees are touching each other or the wind is blowing flames from one place to the next. Contrary to gut feeling, fires do not spread through air with ease—otherwise we’d set the atmosphere ablaze every time we switched on an oven or lit a cigarette.
Provided there is something to start off the fire, the discovery of an SHC victim is not suspicious at all and actually goes along with straightforward science. And it turns out that in most detailed reports of SHC there is an obvious source of ignition.
For example, the death of Nicole Millet (February 20, 1725, Rheims, France) is often cited as spontaneous human combustion since she was found on the floor charred to a crisp with little damage to the surroundings. What has to be factored in is that Millet was a heavy drinker and had gone to “warm herself by the fire” with a bottle of alcohol.19 Hmm.
Similarly, Mary Reeser (July 2, 1951, St. Petersburg, Florida) was found torched in an armchair, again with little damage to the room apart from the chair she was sitting on.20 After investigation, however, the FBI concluded that Reeser was taking sleeping pills, which caused her to fall asleep while smoking.21 Hmm.
As scientists, we have to be skeptical, particularly of strange claims. In most cases, it turns out that while human combustion can happen there is nothing spontaneous about it. And yet …
I don’t know whether spontaneous human combustion happens. Almost all the claims turn out to have obvious causes, but I cannot ignore the fact that one or two do not. Of the few hundred documented cases of SHC in history, there are a handful that seem to defy explanation.
The case of Robert Francis Bailey (September 13, 1967, Lambeth, London) is one such instance. A group of people walking outside a vacant house in London reported a bright flickering light inside and called the fire department, who arrived within minutes. When they entered the house, Brigade Commander John Stacey reported, Bailey’s body was curled on the floor with a four-inch slit in h
is stomach from which a roaring flame emanated. The house’s electric and gas supply had been disconnected and there was no sign of matches anywhere.22 So how did the fire start and why was it bursting from his gut?
Then there’s the account of Raymond Reed, who was with the Ninth Battalion of the Royal Welsh Fusiliers during the Second World War. Reed didn’t combust himself, but recounts one night in Dorset when he was crossing a field and a nearby sheep exploded.23 Presumably the sheep wasn’t smoking in bed.
There’s also the 1867 case of Mr. Watt of Garston whose corpse suddenly began to burn in a church crypt long after his death from typhoid fever.24 Not only is it unlikely he was smoking in bed, he was encased in a coffin.
Accounts like these, if they are to be believed (and that’s a big if), are difficult to rationalize. The wick effect would explain the remains, but there doesn’t seem to be a source of ignition.
We must be careful, though. Just because we don’t have an explanation for something doesn’t mean we have to accept a fanciful one. These accounts can’t be explained, but the sensible thing to do is say we don’t know the explanation, not put in any hypothesis that we like. There’s no reason to assume SHC unless we can find evidence for it directly. Otherwise, we might claim that every unexplained fire is the result of spontaneous combustion.
There is, however, one detail that pervades every account of witnessed spontaneous combustion and might just qualify as potential evidence. The flames are always reported to be bright blue and originating in the gut.
In 1993, Gunter Gassmann and Dieter Glindemann showed that the interior of the human gut is capable of forming a chemical called phosphane (PH3).25 By itself, phosphane isn’t flammable, but if two phosphane molecules are linked together they form diphosphane (P2H4), which is. Diphosphane can spontaneously ignite in the presence of oxygen and burn the other gases in the vicinity. The main gas within the human body is methane (CH4), mostly found in the gut and famous for its blue flame.
Diphosphane often forms in marshland conditions, which is why people occasionally report blue flames around swamps and graveyards. So-called will-o’-the-wisp ghosts are actually methane fires triggered by phosphorus chemistry.
At present, there is no known mechanism that causes diphosphane to form inside the intestines, but if there was and if it came into contact with oxygen and if there was enough methane present, there is a slim chance a fire could conceivably start.
The scientifically honest answer to whether spontaneous human combustion can occur is still “we don’t know.” Diphosphane offers a tantalizing possibility, but speculations are not proofs. What we can say is that if spontaneous human combustion really does happen, it’s a one-in-a-billion chance.
I have made it clear to my friends that if I happen to be one of the few people who dies from spontaneous human combustion, they need to film the entire episode so that other scientists can learn something. So, if you ever meet me and I’m complaining of a stomach problem, cameras at the ready please.
CHAPTER TWELVE
Nine Elements that Changed the World (and One that Didn’t)
THE LONGEST EXPERIMENT IN HISTORY
Classifying something as a solid, a liquid, or a gas is usually straightforward. Solids don’t flow, liquids do but can’t be compressed, and gases are both compressible and capable of flowing. These definitions work for most materials but there are some that aren’t what they first appear, bringing us to our final record-breaking chemical: pitch.
Also called asphalt, pitch is the sticky black residue left over when crude oil is distilled. We use it to make our roads and what makes it interesting is that while it appears solid, it isn’t. The roads you drive on are made of liquid.
In 1902, an unnamed scientist at the Royal Scottish Museum in Edinburgh poured a sample of hot pitch into a glass funnel and left it to cool. For over a hundred years the pitch has oozed through the funnel and two drops have fallen onto a dish below.1 To the naked eye it looks like solid black gunk, but what you’re looking at is the most viscous liquid known to humankind.
A similar version with a slightly runnier pitch was set up in 1927 at the University of Queensland in Brisbane. That one has dripped nine times since the experiment began, with the most recent one falling in 2014.
Time-lapse cameras have captured the slow creeping of these liquids, but nobody has ever witnessed the precise instant when a drop falls. Don’t despair, though. If you go to http://www.thetenthwatch.com/feed you can watch a live broadcast of the Brisbane experiment as the tenth blob of liquid slowly forms. You’re welcome.
These two experiments have been running through both world wars, the rise and fall of the Soviet Union, and the release of every single Fast and Furious movie, making them the longest running experiments in history. But if we wanted to get philosophical for a moment, we could argue that one experiment has been running for even longer and we are right in the middle of it.
What happens if you take a planet’s worth of elements, clump them into a ball orbiting a backwater star, and leave the whole thing for 4.5 billion years? What will happen within the planet’s core and what will happen on its surface?
Humans are a latecomer in a long line of chemical reactions carried out with elements that have been around since before the dinosaurs roamed. The story of the elements is also the story of us and the periodic table has been there for every step, whether we knew it or not.
So, in the final chapter, I want to examine which of the elements have been crucial to our development and which ones have had the biggest impact on this experiment called humanity.
COME BACK ZINC!
There’s an episode of The Simpsons where Bart is forced to watch a video about a kid called Jimmy who wishes to live in a world without zinc. He soon discovers his car battery no longer exists, preventing him from picking up his girlfriend Betty. Not only that, the rotary mechanism on his phone has vanished, as has the firing pin in the gun with which he tries to commit suicide. Jimmy suddenly wakes up screaming, “Come back zinc!” and breathes a sigh of relief. It was all a terrifying dream.2
It’s a perfect satire of the hokey educational videos popular in the 1950s, because nobody has ever wished to live in a world without zinc. I do know someone who considers zinc her favorite element, but most people probably know little about it.
And that’s true for most of the elements on the table. We know they exist but don’t give much thought to what they do. If you suffer from kidney problems then you should thank zirconium because it’s used in dialysis machines for absorbing ions. If you’re a smoker you owe your habit to cerium because it’s one of the only metals that produces sparks, allowing your lighter to function.
If you work in welding, your goggles are tinted with praseodymium to block yellow light. Or perhaps you work in the solar-panel industry; if so, ruthenium is the element to get excited about because it absorbs sunlight better than anything else.
The microwave you use to heat your meals wouldn’t function without samarium. The fountain pen you used in school had a nib made of iridium and if you live in mainland Europe the dollar bills you spend are impregnated with europium to detect forgery.
Everyone will have their own favorite element (and if it’s not phosphorus, what’s wrong with you?) but we can make a case for some having played a more important role than others.
We could argue that aluminum has been more important than selenium, for instance. One is used in construction and vehicle manufacture while the other is used to decolorize glass and eliminate dandruff. (Having said that, I do enjoy looking through my windows while running my fingers through a fine crop of healthy hair.)
If we ignore obvious and boring choices like the oxygen we breathe or the iron in our planetary core, which elements have played the most crucial roles in our cultural, political, and technological evolution? Which ones have made the world what it is, and which ones are secretly influencing our daily lives without us even noticing?
This has
been a difficult list to compose because as soon as I settled on one selection I immediately felt I was leaving an important element out. The problem is that every element is special. Well, all except for one.
AN HONORARY MENTION
Originally I intended this chapter to be a conventional top-ten list, but in the end I went for nine. The reason is that there’s one element that deserves a very special mention but doesn’t quite fit with the others.
In the process of researching this book I learned the stories and characteristics of all 118 known elements. Every one is unique either because it played an important role in the history of chemistry or because it has a distinct property making it ideal for a particular use.
I have succeeded in namechecking every element somewhere in the book at least once, with the exception of element number 66—dysprosium. The most pointless element in the world.
Dysprosium was isolated by Paul-Émile Lecoq on his mantelpiece in 1886 and that seems appropriate.3 It’s a mantelpiece element if ever there was one. It exists and it probably has a purpose, but nobody knows what it is.
Dysprosium is neither especially rare nor especially common. It reacts with water but not as well as group 1 metals. It can be used to make lasers but they’re not as good as those made from helium or neon. It’s occasionally used in nuclear control rods, which stop things getting too hot, but you can achieve the same effect with indium or cadmium. Dysprosium is beaten at every turn by something else.
There will definitely be a dysprosium scientist out there who’s currently foaming at the mouth as she reads this. But dysprosium doesn’t seem to be exclusive in any way, which makes it quite interesting.
I hereby declare dysprosium to be the only element you could remove from human history and absolutely nothing much would change. We salute you, dysprosium, the most boring element on the periodic table.
